Protocormlike bodies (PLBs) regeneration system has been established for several Rosa spp. More understandings on the process of PLBs formation, including what roles of vascular tissue of rhizoids play in the incipient stage, will contribute to the establishment of PLBs protocols in cut roses. We proposed a hypothesis named ‘vascular channel’: Through the vascular tissue in R. canina rhizoids, high concentration of TDZ (thidiazuron) containing in medium was quickly and largely transported to rhizoid meristem, resulting in the rhizoid meristem cells shifting their functions, which initiated PLBs development. In the present study, we provided some evidence on the rationality of this hypothesis. Both whole callusfree rhizoids and its segments were cultured either vertically or horizontally on the induction medium with TDZ, no PLBs formed. During the bridging culture, the efficiency of PLBs induction was higher in the callusrhizoids relied on apoplastic transport than symplastic transport. The TIBA (2, 3, 5triiodobenzoic acid) treatment had suppressed the elongation of vascular tissue towards to the rhizoid meristem, which finally led to a low rate of PLBs formation. Furthermore, the partial process of PLBs system was reproduced in Medicago truncatula Gaertn., their rhizoid tips derived from the rhizoid segment were induced into green ellipsoidal bodies. These findings indicated that the vascular tissue of R. canina callus  rhizoids being capable of rapidly delivering nutrients and hormones was critical for PLBs development, and it must be closed and complete from the callus to the rhizoid tip. Based on this, we proposed that the prerequisite for achieving a PLBs system of cut roses is to induce callusrhizoids or similar explants possessing a transporting system that could rapidly aggregate hormones and nutrients.